JP3509585B2 - Watt hour meter - Google Patents
Watt hour meterInfo
- Publication number
- JP3509585B2 JP3509585B2 JP33390998A JP33390998A JP3509585B2 JP 3509585 B2 JP3509585 B2 JP 3509585B2 JP 33390998 A JP33390998 A JP 33390998A JP 33390998 A JP33390998 A JP 33390998A JP 3509585 B2 JP3509585 B2 JP 3509585B2
- Authority
- JP
- Japan
- Prior art keywords
- voltage
- current
- instantaneous
- value
- measuring means
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Landscapes
- Measurement Of Current Or Voltage (AREA)
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、交流配線路上で負
荷への電力の供給経路に取り付けられ、負荷に供給した
電力量を求めて表示する電力量計に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a watt hour meter attached to a power supply path for a load on an AC wiring path and for displaying the electric power quantity supplied to the load.
【０００２】[0002]
【従来の技術】この種の電力量計として、最近では交流
配線路の電圧値と電流値とを乗算するとともに時間につ
いて積分（つまり積算）することによって電力量を求め
るものが提供されている。この種の電力量計では、交流
配線路の各線路にプローブを接続することによってプロ
ーブ間の電圧値を求め、また電流センサを用いることに
よって交流配線路の通過電流を求めている。電流センサ
には、環状コアに検出用の巻線を巻き付けるとともに環
状コアの一部を開閉可能とした変流器が広く用いられて
いる。この種の電流センサは環状コアを開いて交流配線
路を環状コア内に導入した後に環状コアを閉じるから、
環状コア内に交流配線路を貫通させた形に拘束すること
になり、この意味でクランプセンサと呼称されている。2. Description of the Related Art Recently, as an electric energy meter of this type, there has been provided an electric energy meter which multiplies a voltage value and an electric current value of an AC wiring path and integrates (that is, integrates) time. In this kind of watt hour meter, a voltage value between the probes is obtained by connecting a probe to each line of the AC wiring line, and a passing current of the AC wiring line is obtained by using a current sensor. A current transformer in which a winding for detection is wound around an annular core and a part of the annular core can be opened and closed is widely used as a current sensor. Since this type of current sensor closes the annular core after opening the annular core and introducing the AC wiring path into the annular core,
The AC wiring path is constrained to pass through the annular core, and in this sense, it is called a clamp sensor.
【０００３】プローブおよび電流センサでは電圧値およ
び電流値の瞬時値（アナログ値）が得られるから、マイ
コンを用いた演算手段によって電圧値および電流値の最
低値から最高値までの値（ピーク・トゥ・ピーク値）を
Ａ／Ｄ変換してデジタルの電圧値と電流値とを求めて乗
算し時間について積分することで電力量を求めることが
できる。また、電力量計には求めた電力量を表示するた
めの表示手段が設けられるSince the probe and the current sensor obtain the instantaneous value (analog value) of the voltage value and the current value, the value (peak to peak value) from the lowest value to the highest value of the voltage value and the current value is calculated by the calculating means using the microcomputer. The electric energy can be obtained by A / D converting the (peak value) to obtain the digital voltage value and the current value, multiplying them, and integrating with respect to time. Further, the watt hour meter is provided with display means for displaying the obtained amount of power.
【０００４】[0004]
【発明が解決しようとする課題】上述した従来例の電力
量計にあっては、プローブ間の電圧値と電流センサで検
出される電流値とをそのままＡ／Ｄ変換して演算手段で
電力量を求めているから、Ａ／Ｄ変換の分解能を大きく
しないと電力量を正確に測定することができないという
問題があった。In the conventional watt hour meter described above, the voltage value between the probes and the current value detected by the current sensor are A / D converted as they are, and the electric energy is calculated by the arithmetic means. Therefore, there is a problem that the electric energy cannot be accurately measured unless the resolution of A / D conversion is increased.
【０００５】本発明は上記問題点の解決を目的とするも
のであり、積算電力量を正確に測定することができる電
力量計を提供しようとするものである。An object of the present invention is to solve the above problems, and an object of the present invention is to provide an electric energy meter capable of accurately measuring an integrated electric energy.
【０００６】[0006]
【課題を解決するための手段】請求項１の発明は、上記
目的を達成するために、交流配線路に供給される電圧お
よび電流を測定する電圧電流測定手段と、電圧電流測定
手段により測定された瞬時電圧値および瞬時電流値をＡ
／Ｄ変換した後に乗算して交流配線路を通過した瞬時電
力を求めるとともに瞬時電力を積算することで積算電力
量を求める演算手段と、演算手段により求めた積算電力
量を表示する表示手段とを備えた電力量計において、電
圧電流測定手段は、交流配線路に供給される電圧および
電流の極性を検出する極性検出部と、交流配線路から取
り出された電圧および電流を全波整流する整流部とを具
備し、演算手段は、整流部で全波整流された電圧および
電流をＡ／Ｄ変換して得られる瞬時電圧値および瞬時電
流値に極性検出部で検出された極性に対応する符号を付
して乗算することで瞬時電力を求めることを特徴とし、
交流配線路から取り出された電圧および電流をＡ／Ｄ変
換前に全波整流しているから、従来に比べて見かけ上の
分解能が高まり、積算電力量を正確に測定することがで
きる。In order to achieve the above-mentioned object, the invention of claim 1 is a voltage / current measuring means for measuring a voltage and a current supplied to an AC wiring path, and a voltage / current measuring means. The instantaneous voltage value and instantaneous current value
A calculation unit that calculates the integrated power amount by multiplying after the D / D conversion to obtain the instantaneous power that has passed through the AC wiring path and integrating the instantaneous power, and a display unit that displays the integrated power amount calculated by the calculation unit. In the watt-hour meter provided, the voltage / current measuring means includes a polarity detecting section that detects the polarities of the voltage and the current supplied to the AC wiring path, and a rectifying section that performs full-wave rectification on the voltage and the current extracted from the AC wiring path. The arithmetic means includes an instantaneous voltage value and an instantaneous current value obtained by A / D converting the full-wave rectified voltage and current in the rectifying unit, and adds a code corresponding to the polarity detected by the polarity detecting unit. It is characterized by obtaining the instantaneous power by adding and multiplying,
Since the voltage and current extracted from the AC wiring line are full-wave rectified before A / D conversion, the apparent resolution is higher than in the conventional case, and the integrated electric energy can be accurately measured.
【０００７】請求項２の発明は、請求項１の発明におい
て、交流配線から取り出される電圧および電流を増幅す
る増幅部が電圧電流測定手段に設けられ、演算手段は、
電圧電流測定手段で測定された瞬時電圧値あるいは瞬時
電流値が所定値以下となったときに増幅部における増幅
度を可変することを特徴とし、測定精度を向上させるこ
とができる。According to a second aspect of the invention, in the first aspect of the invention, the voltage / current measuring means is provided with an amplifying section for amplifying the voltage and the current taken out from the AC wiring, and the calculating means is
It is characterized in that when the instantaneous voltage value or the instantaneous current value measured by the voltage / current measuring means becomes equal to or less than a predetermined value, the amplification degree in the amplification section is changed, and the measurement accuracy can be improved.
【０００８】[0008]
【発明の実施の形態】以下の説明では、図２のように、
単相３線式あるいは三相３線式のように交流電源ＡＣと
負荷ＬＤとを接続する３本の線路Ｌ１〜Ｌ３を備える交
流配線路Ｌを想定する。本実施形態は、交流配線路Ｌの
各線路Ｌ１〜Ｌ３に接続されて線間電圧を検出する３個
のプローブＰ１〜Ｐ３と、交流配線路Ｌのうちの２本の
線路Ｌ１、Ｌ３がそれぞれ貫通される２個の電流センサ
ＣＴ１、ＣＴ２とを備える。電流センサＣＴ１、ＣＴ２
は従来例でも説明したように開閉可能な環状コアを備え
る変流器を用いている。BEST MODE FOR CARRYING OUT THE INVENTION In the following description, as shown in FIG.
Assume an AC wiring path L including three lines L1 to L3 connecting the AC power source AC and the load LD, such as a single-phase three-wire system or a three-phase three-wire system. In this embodiment, three probes P1 to P3 connected to the lines L1 to L3 of the AC wiring line L to detect the line voltage and two lines L1 and L3 of the AC wiring line L are respectively provided. It is provided with two current sensors CT1 and CT2 penetrating therethrough. Current sensor CT1, CT2
Uses a current transformer having an openable and closable annular core as described in the conventional example.
【０００９】図１に示すように、プローブＰ１〜Ｐ３は
電圧入力部１１の一部を構成し、電流センサＣＴ１，Ｃ
Ｔ２は電流入力部１２の一部を構成する。電圧入力部１
１および電流入力部１２には、交流電源ＡＣから交流配
線路Ｌを通して負荷ＬＤに供給される電力を検出するの
に不要な周波数成分を除去するためのフィルタや電流−
電流変換回路並びに増幅回路などが適宜設けられる。電
圧入力部１１および電流入力部１２によりそれぞれ検出
された電圧値および電流値は、電力量を求める演算を行
う前に前処理回路１３に入力され、電圧値および電流値
の極性と絶対値とが求められる。すなわち、前処理回路
１３は、プローブＰ２に印加される電圧を基準電位（０
Ｖ）とするときの他のプローブＰ１，Ｐ３の電圧の極性
をそれぞれ検出する極性検出回路１４ａ，１４ｂを備え
るとともに、両電圧を全波整流する整流回路１５ａ，１
５ｂを備える。また、前処理回路１３は、２つの電流セ
ンサＣＴ１，ＣＴ２により検出された電流の極性をそれ
ぞれ検出する極性検出回路１６ａ，１６ｂを備えるとと
もに、両電流を全波整流する整流回路１７ａ，１７ｂを
備える。而して、本実施形態では、電圧入力部１１，電
流入力部１２並びに前処理回路１３にて電圧電流測定手
段が構成されている。As shown in FIG. 1, the probes P1 to P3 constitute a part of the voltage input section 11, and the current sensors CT1 and C1.
T2 constitutes a part of the current input unit 12. Voltage input section 1
1 and the current input unit 12 include a filter and a current for removing a frequency component unnecessary for detecting the power supplied to the load LD from the AC power source AC through the AC wiring path L.
A current conversion circuit, an amplification circuit, and the like are appropriately provided. The voltage value and the current value respectively detected by the voltage input unit 11 and the current input unit 12 are input to the preprocessing circuit 13 before the calculation for obtaining the electric energy, and the polarities and absolute values of the voltage value and the current value are determined. Desired. That is, the preprocessing circuit 13 changes the voltage applied to the probe P2 to the reference potential (0
V), the polarity detection circuits 14a and 14b for respectively detecting the polarities of the voltages of the other probes P1 and P3 are provided, and the rectification circuits 15a and 1 for full-wave rectifying both voltages are provided.
5b. Further, the preprocessing circuit 13 includes polarity detection circuits 16a and 16b that detect the polarities of the currents detected by the two current sensors CT1 and CT2, respectively, and also includes rectification circuits 17a and 17b that perform full-wave rectification on both currents. . Thus, in this embodiment, the voltage input section 11, the current input section 12, and the preprocessing circuit 13 constitute a voltage / current measuring means.
【００１０】各極性検出回路１４ａ，１４ｂ，１６ａ，
１６ｂは、それぞれ電圧波形や電流波形のゼロクロス点
を検出するとともに隣接するゼロクロス点間の極性に応
じた２値の信号を発生するように構成されている。した
がって、プローブＰ１〜Ｐ３ないし電流センサＣＴ１，
ＣＴ２により検出される交流電圧ないし交流電流が、た
とえば図３（ａ）のような正弦波であれば、各極性検出
回路１４ａ，１４ｂ，１６ａ，１６ｂの出力は図３
（ｂ）のような矩形波信号になる。また、整流回路１５
ａ，１５ｂ，１７ａ，１７ｂの出力は、図３（ｃ）のよ
うな脈流波形になる。Each polarity detection circuit 14a, 14b, 16a,
16b is configured to detect the zero cross points of the voltage waveform and the current waveform, respectively, and generate a binary signal corresponding to the polarity between the adjacent zero cross points. Therefore, the probes P1 to P3 or the current sensors CT1,
If the AC voltage or the AC current detected by CT2 is a sine wave as shown in FIG. 3A, the output of each polarity detection circuit 14a, 14b, 16a, 16b will be as shown in FIG.
A rectangular wave signal as shown in (b) is obtained. In addition, the rectifier circuit 15
The outputs of a, 15b, 17a and 17b have a pulsating flow waveform as shown in FIG.
【００１１】極性検出回路１４ａ，１４ｂ，１６ａ，１
６ｂにより検出された交流電圧ないし交流電流の極性
と、整流回路１５ａ，１５ｂ，１７ａ，１７ｂにより検
出された交流電圧ないし交流電流の絶対値とは、それぞ
れマイコンを主構成とする演算回路２１を備えた演算手
段２０に入力される。演算回路２１は、各整流回路１５
ａ，１５ｂ，１７ａ，１７ｂの出力をＡ／Ｄ変換する機
能を有し、Ａ／Ｄ変換後のデジタル値には極性検出回路
１４ａ，１４ｂ，１６ａ，１６ｂにより検出された極性
に対応する符号が付加される。Polarity detection circuits 14a, 14b, 16a, 1
The polarity of the AC voltage or the AC current detected by 6b and the absolute value of the AC voltage or the AC current detected by the rectifier circuits 15a, 15b, 17a, 17b are provided with an arithmetic circuit 21 mainly composed of a microcomputer. It is input to the calculating means 20. The arithmetic circuit 21 includes each rectifying circuit 15
It has a function of A / D converting the outputs of a, 15b, 17a, 17b, and the digital value after A / D conversion has a code corresponding to the polarity detected by the polarity detection circuits 14a, 14b, 16a, 16b. Is added.
【００１２】ここにおいて、Ａ／Ｄ変換を行う対象が脈
流波形であることによって、Ａ／Ｄ変換器のダイナミッ
クレンジを変更せずに交流波形（図３（ａ）参照）にＡ
／Ｄ変換を施す場合と比較すると、１ビット当たりのス
テップ幅を小さくすることができ、結果的に分解能を高
めたことになる。こうして求めた交流電圧および交流電
流の瞬時値に対応する符号付きのデジタル値を乗算す
る。ここで、Ａ／Ｄ変換の際のサンプリング周期を適宜
に（交流電源ＡＣの周期よりも十分に短い周期に）設定
しておき、交流電源ＡＣの１周期分の乗算値の総和を求
めた後にサンプリング数で除算すれば、この値が瞬時電
力に相当することになる。また、所望期間の電力量は、
その期間における瞬時電力の総和を求める。この演算は
電力の時間についての積分を行うことに相当する。Here, since the object to be A / D converted is the pulsating flow waveform, the AC waveform (see FIG. 3 (a)) is converted into an AC waveform without changing the dynamic range of the A / D converter.
Compared with the case of performing / D conversion, the step width per bit can be reduced, resulting in higher resolution. The signed digital values corresponding to the instantaneous values of the alternating voltage and alternating current thus obtained are multiplied. Here, the sampling cycle for A / D conversion is appropriately set (to a cycle that is sufficiently shorter than the cycle of the AC power supply AC), and after the sum of the multiplication values for one cycle of the AC power supply AC is obtained. When divided by the number of samplings, this value corresponds to the instantaneous power. Also, the amount of power for the desired period is
The total sum of the instantaneous power in that period is calculated. This calculation corresponds to the integration of electric power with respect to time.
【００１３】演算回路２１において電力を求める演算の
手順を示すと図４のようになる。つまり、交流電圧の絶
対値に相当する整流回路１５ａ，１５ｂの出力をＡ／Ｄ
変換した後（Ｓ１）、極性検出回路１４ａ，１４ｂによ
り検出した符号を入力して（Ｓ２）、Ａ／Ｄ変換により
得られたデジタル値に符号を付加する（Ｓ３）。また、
交流電流の絶対値に相当する整流回路１７ａ，１７ｂの
出力をＡ／Ｄ変換した後（Ｓ４）、極性検出回路１６
ａ，１６ｂにより検出した符号を入力して（Ｓ５）、Ａ
／Ｄ変換により得られたデジタル値に符号を付加する
（Ｓ６）。このようにしてステップＳ３，Ｓ６により交
流電源の電圧値および電流値に相当する値Ｖ１，Ｉ１が
求められると、演算手段１０ではこれらの値Ｖ１，Ｉ１
の乗算値（＝Ｖ１×Ｉ１）を瞬時値Ｗ１として求める
（Ｓ７）。求めた瞬時値Ｗ１は順次加算され（Ｓ８）、
交流電源ＡＣの電圧波形の１周期分について瞬時値Ｗ１
の加算値Ｗ０を求めた後（Ｓ９）、この加算値Ｗ０をサ
ンプル数Ｎで除算するのである（Ｓ１０）。こうして求
めた除算値は瞬時電力に相当する。FIG. 4 shows the calculation procedure for calculating the electric power in the calculation circuit 21. That is, the outputs of the rectifier circuits 15a and 15b corresponding to the absolute value of the AC voltage are converted into A / D values.
After conversion (S1), the code detected by the polarity detection circuits 14a and 14b is input (S2), and the code is added to the digital value obtained by A / D conversion (S3). Also,
After A / D conversion of the outputs of the rectifier circuits 17a and 17b corresponding to the absolute value of the alternating current (S4), the polarity detection circuit 16
Input the code detected by a and 16b (S5), A
A code is added to the digital value obtained by the / D conversion (S6). In this way, when the values V1 and I1 corresponding to the voltage value and the current value of the AC power supply are obtained in steps S3 and S6, the arithmetic means 10 calculates these values V1 and I1.
The multiplication value (= V1 × I1) of is calculated as the instantaneous value W1 (S7). The obtained instantaneous values W1 are sequentially added (S8),
Instantaneous value W1 for one cycle of the voltage waveform of the AC power supply AC
After obtaining the additional value W0 of (S9), this additional value W0 is divided by the number of samples N (S10). The division value thus obtained corresponds to the instantaneous power.
【００１４】ところで、演算回路２１において求めた交
流電圧および交流電流の瞬時値に対応する符号付きのデ
ジタル値が、所定の値よりも小さくて十分な測定精度が
得られない場合がある。そこで、本実施形態において
は、電圧入力部１１並びに電流入力部１２に設けられて
検出された電圧値および電流値を増幅する増幅回路（図
示せず）の増幅度を、演算回路２１によって可変とし、
上述のように交流電圧および交流電流の瞬時値に対応す
る符号付きのデジタル値が所定値以下の場合に演算回路
２１が上記増幅回路の増幅度を上げるように動作する。
これにより、プローブＰ１〜Ｐ３で検出される交流電圧
や電流センサＣＴ１，ＣＴ２で検出される交流電流の絶
対値が小さい場合でも充分な精度で瞬時電力を測定する
ことが可能となる。By the way, there are cases where the signed digital values corresponding to the instantaneous values of the AC voltage and the AC current obtained by the arithmetic circuit 21 are smaller than a predetermined value and sufficient measurement accuracy cannot be obtained. Therefore, in the present embodiment, the amplification degree of an amplifier circuit (not shown) provided in the voltage input section 11 and the current input section 12 for amplifying the detected voltage value and current value is made variable by the arithmetic circuit 21. ,
As described above, the arithmetic circuit 21 operates to increase the amplification degree of the amplifier circuit when the signed digital values corresponding to the instantaneous values of the AC voltage and the AC current are equal to or less than the predetermined value.
This makes it possible to measure the instantaneous power with sufficient accuracy even when the AC voltage detected by the probes P1 to P3 and the absolute value of the AC current detected by the current sensors CT1 and CT2 are small.
【００１５】ところで、電力量は週毎、日毎、時間毎な
ど、決まった期間内で求めることが多く、これらの期間
は演算手段２０に設けた時計部２３で計時される。つま
り、動作が開始されると時計部２３によって週、日、時
間の区切りを示す信号が演算回路２１に入力され、演算
回路２１にこの信号が入力されると、対応する期間内の
電力量がＥＥＰＲＯＭよりなる記憶部２２に書き込ま
れ、また古くなった不要なデータは記憶部２２から消去
される。時計部２３は電力量の測定を開始した時点から
の経過時間を計時する機能も有している。演算手段２０
には表示手段としての液晶表示器３１およびキーパッド
３２を備えた表示操作部３０が接続される。By the way, the amount of electric power is often obtained within a fixed period such as weekly, daily, or hourly, and these periods are clocked by the clock unit 23 provided in the calculating means 20. That is, when the operation is started, the clock section 23 inputs a signal indicating a break of week, day, and time to the arithmetic operation circuit 21, and when this signal is input to the arithmetic operation circuit 21, the electric energy in the corresponding period is changed. Unnecessary data that has been written to the storage unit 22 including an EEPROM and has become old is erased from the storage unit 22. The clock unit 23 also has a function of measuring the elapsed time from the time when the measurement of the electric energy is started. Computing means 20
A display operation unit 30 including a liquid crystal display 31 as a display unit and a keypad 32 is connected to the.
【００１６】ところで、前処理回路１３、演算手段２
０、表示操作部３０などの内部電源は、プローブＰ１，
Ｐ２を通して交流配線路Ｌから供給される。すなわち、
プローブＰ１，Ｐ２には電源回路４０が接続され、この
電源回路４０から直流定電圧を出力して内部電源に用い
ている。このように内部電源を生成する電源回路４０に
は、プローブＰ１，Ｐ２を通して交流配線路Ｌから電力
を供給しているから、内部電源として電池を用いたり、
内部電源を得るためのアダプタを別途に設けたりする必
要がなく、交流配線路Ｌへの接続作業が容易になってい
る。By the way, the preprocessing circuit 13 and the calculating means 2
0, the internal power source such as the display operation unit 30 is the probe P1,
It is supplied from the AC wiring line L through P2. That is,
A power supply circuit 40 is connected to the probes P1 and P2, and a constant DC voltage is output from the power supply circuit 40 and used as an internal power supply. As described above, since power is supplied from the AC wiring line L to the power supply circuit 40 for generating the internal power supply through the probes P1 and P2, a battery may be used as the internal power supply,
Since it is not necessary to separately provide an adapter for obtaining the internal power source, the connection work to the AC wiring path L is facilitated.
【００１７】ところで、交流電源ＡＣは停電することが
あり、停電が生じたときに時計部２３への電力供給が停
止すると、復電時に時計部２３を合わせ直すことが必要
になり、手間がかかるものである。そこで、電源回路４
０から演算手段２０への電源供給が停止しても時計部２
３には電源を供給することができるようにバックアップ
電源回路４７を設けている。バックアップ電源回路４７
は２次電池を用いたものであり、この２次電池は通常時
に電源回路４０の出力電圧により充電され、停電時には
時計部２３に電源を供給するように構成されている。し
たがって、停電中であっても時計部２３は正常に動作
し、復電時における時刻合わせが不要になっている。し
かも、２次電池であるから長期間に亘って交換が不要で
あり、さらには通常時に２次電池が充電されているか
ら、別途に２次電池を充電する必要もないのである。By the way, the AC power supply AC may have a power failure, and if the power supply to the clock section 23 is stopped when the power failure occurs, it is necessary to re-adjust the clock section 23 when the power is restored, which is troublesome. It is a thing. Therefore, the power supply circuit 4
Even if the power supply from 0 to the computing means 20 is stopped, the clock unit 2
3 is provided with a backup power supply circuit 47 so that power can be supplied. Backup power supply circuit 47
Uses a secondary battery, which is normally charged by the output voltage of the power supply circuit 40, and is configured to supply power to the clock unit 23 in the event of a power failure. Therefore, the clock unit 23 operates normally even during a power failure, and the time adjustment at the time of power recovery is unnecessary. Moreover, since it is a secondary battery, it does not need to be replaced for a long period of time, and since the secondary battery is normally charged, it is not necessary to separately charge the secondary battery.
【００１８】上述のように本実施形態によれば、演算回
路２１にて瞬時電圧値および瞬時電流値を求めるために
Ａ／Ｄ変換を行う対象が脈流波形であることによって、
Ａ／Ｄ変換器のダイナミックレンジを変更せずに交流波
形にＡ／Ｄ変換を施す場合と比較すると、１ビット当た
りのステップ幅を小さくすることができ、結果的に分解
能を高めたことになるから、積算電力量を正確に測定す
ることができるものである。As described above, according to this embodiment, the object to be A / D converted in order to obtain the instantaneous voltage value and the instantaneous current value in the arithmetic circuit 21 is the pulsating flow waveform.
Compared with the case where A / D conversion is performed on an AC waveform without changing the dynamic range of the A / D converter, the step width per bit can be reduced, resulting in higher resolution. Therefore, the integrated electric energy can be accurately measured.
【００１９】[0019]
【発明の効果】請求項１の発明は、交流配線路に供給さ
れる電圧および電流を測定する電圧電流測定手段と、電
圧電流測定手段により測定された瞬時電圧値および瞬時
電流値をＡ／Ｄ変換した後に乗算して交流配線路を通過
した瞬時電力を求めるとともに瞬時電力を積算すること
で積算電力量を求める演算手段と、演算手段により求め
た積算電力量を表示する表示手段とを備えた電力量計に
おいて、電圧電流測定手段は、交流配線路に供給される
電圧および電流の極性を検出する極性検出部と、交流配
線路から取り出された電圧および電流を全波整流する整
流部とを具備し、演算手段は、整流部で全波整流された
電圧および電流をＡ／Ｄ変換して得られる瞬時電圧値お
よび瞬時電流値に極性検出部で検出された極性に対応す
る符号を付して乗算することで瞬時電力を求めるので、
交流配線路から取り出された電圧および電流をＡ／Ｄ変
換前に全波整流することで従来に比べて見かけ上の分解
能が高まり、積算電力量を正確に測定することができる
という効果がある。According to the first aspect of the present invention, the voltage / current measuring means for measuring the voltage and current supplied to the AC wiring path, and the instantaneous voltage value and the instantaneous current value measured by the voltage / current measuring means are A / D. A conversion means for calculating the integrated electric power amount by accumulating the instantaneous electric power which has been converted and multiplied to obtain the instantaneous electric power passing through the AC wiring path, and a display means for displaying the integrated electric power amount obtained by the arithmetic operation means are provided. In the watt-hour meter, the voltage / current measuring means includes a polarity detection unit that detects the polarities of the voltage and current supplied to the AC wiring line, and a rectification unit that full-wave rectifies the voltage and current extracted from the AC wiring line. The arithmetic means adds the sign corresponding to the polarity detected by the polarity detection unit to the instantaneous voltage value and the instantaneous current value obtained by A / D converting the voltage and current that are full-wave rectified by the rectification unit. Ride Since determine the instantaneous power by,
By performing full-wave rectification on the voltage and current extracted from the AC wiring path before A / D conversion, apparent resolution is improved as compared with the related art, and the integrated electric energy can be accurately measured.
【００２０】請求項２の発明は、交流配線から取り出さ
れる電圧および電流を増幅する増幅部が電圧電流測定手
段に設けられ、演算手段は、電圧電流測定手段で測定さ
れた瞬時電圧値あるいは瞬時電流値が所定値以下となっ
たときに増幅部における増幅度を可変するので、測定精
度を向上させることができるという効果がある。According to a second aspect of the present invention, the voltage / current measuring means is provided with an amplifying section for amplifying the voltage and the current taken out from the AC wiring, and the arithmetic means is the instantaneous voltage value or the instantaneous current measured by the voltage / current measuring means. When the value becomes less than or equal to the predetermined value, the amplification degree in the amplification section is changed, so that there is an effect that the measurement accuracy can be improved.
【図１】本発明の実施の形態を示すブロック図である。FIG. 1 is a block diagram showing an embodiment of the present invention.
【図２】同上の使用形態を示す概略図である。FIG. 2 is a schematic view showing a usage pattern of the above.
【図３】同上の動作説明図である。FIG. 3 is an operation explanatory diagram of the above.
【図４】同上の動作説明図である。FIG. 4 is an operation explanatory diagram of the above.
１１ 電圧入力部 １２ 電流入力部 １３ 前処理回路 ２０ 演算手段 ＣＴ１，ＣＴ２ 電流センサ Ｌ 交流配線路 Ｐ１〜Ｐ３ プローブ 11 Voltage input section 12 Current input section 13 Preprocessing circuit 20 Calculation means CT1, CT2 current sensor L AC wiring route P1 to P3 probes
───────────────────────────────────────────────────── フロントページの続き (56)参考文献 特開 昭64−43766（ＪＰ，Ａ) 特開 昭56−14959（ＪＰ，Ａ) 特開 平５−34387（ＪＰ，Ａ) 特開 昭62−280654（ＪＰ，Ａ) (58)調査した分野(Int.Cl.7，ＤＢ名) G01R 21/00 - 22/00 130 G01R 11/00 - 11/66 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A 64-43766 (JP, A) JP-A 56-14959 (JP, A) JP-A 5-34387 (JP, A) JP-A 62- 280654 (JP, A) (58) Fields surveyed (Int.Cl. 7 , DB name) G01R 21/00-22/00 130 G01R 11/00-11/66
Claims (2)
を測定する電圧電流測定手段と、電圧電流測定手段によ
り測定された瞬時電圧値および瞬時電流値をＡ／Ｄ変換
した後に乗算して交流配線路を通過した瞬時電力を求め
るとともに瞬時電力を積算することで積算電力量を求め
る演算手段と、演算手段により求めた積算電力量を表示
する表示手段とを備えた電力量計において、電圧電流測
定手段は、交流配線路に供給される電圧および電流の極
性を検出する極性検出部と、交流配線路から取り出され
た電圧および電流を全波整流する整流部とを具備し、演
算手段は、整流部で全波整流された電圧および電流をＡ
／Ｄ変換して得られる瞬時電圧値および瞬時電流値に極
性検出部で検出された極性に対応する符号を付して乗算
することで瞬時電力を求めることを特徴とする電力量
計。1. A voltage-current measuring means for measuring a voltage and a current supplied to an AC wiring line, and an AC voltage obtained by A / D converting the instantaneous voltage value and the instantaneous current value measured by the voltage-current measuring means and then multiplying them. In a watt-hour meter equipped with a calculating means for calculating the integrated electric energy by accumulating the instantaneous electric power and the instantaneous electric power passing through the wiring path, and a display means for displaying the integrated electric energy calculated by the arithmetic means, The measuring means comprises a polarity detecting section for detecting the polarities of the voltage and the current supplied to the AC wiring path, and a rectifying section for full-wave rectifying the voltage and the current extracted from the AC wiring path. The voltage and current that are full-wave rectified by the rectifier are
A watt hour meter characterized by obtaining instantaneous power by adding a sign corresponding to a polarity detected by a polarity detection unit to an instantaneous voltage value and an instantaneous current value obtained by D / D conversion, and multiplying.
流を増幅する増幅部が電圧電流測定手段に設けられ、演
算手段は、電圧電流測定手段で測定された瞬時電圧値あ
るいは瞬時電流値が所定値以下となったときに増幅部に
おける増幅度を可変することを特徴とする請求項１記載
の電力量計。2. An amplifying section for amplifying a voltage and a current taken out from the AC wiring is provided in the voltage / current measuring means, and the calculating means has an instantaneous voltage value or an instantaneous current value measured by the voltage / current measuring means of a predetermined value or less. The watt-hour meter according to claim 1, wherein the amplification degree in the amplification unit is changed when it becomes.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP33390998A JP3509585B2 (en) | 1998-11-25 | 1998-11-25 | Watt hour meter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP33390998A JP3509585B2 (en) | 1998-11-25 | 1998-11-25 | Watt hour meter |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2000162254A JP2000162254A (en) | 2000-06-16 |
| JP3509585B2 true JP3509585B2 (en) | 2004-03-22 |
Family
ID=18271321
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP33390998A Expired - Fee Related JP3509585B2 (en) | 1998-11-25 | 1998-11-25 | Watt hour meter |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3509585B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107632197B (en) * | 2017-09-05 | 2019-09-03 | 加特兰微电子科技(上海)有限公司 | A kind of radio frequency power meter and signal sending and receiving equipment |
-
1998
- 1998-11-25 JP JP33390998A patent/JP3509585B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JP2000162254A (en) | 2000-06-16 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4261037A (en) | System for monitoring utility usage | |
| CA1254619A (en) | Low cost self-contained transformerless solid state electronic watthour meter having thin film ferromagnetic current sensor | |
| JPH1056744A (en) | Power supply equipped with sealed lead-acid battery | |
| KR102193414B1 (en) | Method And Apparatus for Measuring Power Electric Vehicle | |
| CA2501270C (en) | Bias technique for electric utility meter | |
| EP0240102A2 (en) | Power meter having self-test function | |
| KR20060089729A (en) | Magnetic bridge electric power sensor | |
| JPH0772740B2 (en) | Power detector | |
| JP3509585B2 (en) | Watt hour meter | |
| KR100198229B1 (en) | Electric power applied complex apparatus enable to remotely control and watch | |
| JP3056046B2 (en) | Small power consumption measuring device | |
| JPH0535833B2 (en) | ||
| JP2001124806A (en) | Three-phase power meter, three-phase watt-hour meter, and connection state judging method of them | |
| JP2000162252A (en) | Watthour meter | |
| KR20110068446A (en) | Method of trouble diagnosis for synchronous generator | |
| JP3671706B2 (en) | Electricity meter | |
| JP3850184B2 (en) | Electricity meter | |
| JPH0843460A (en) | High-harmonic measurement analysis system | |
| JP3246309B2 (en) | Deterioration detection device for zinc oxide arrester | |
| MXPA02007467A (en) | Method and apparatus for determining the internal impedance of a distribution transformer and sensing dc current through an ac power meter. | |
| JP3995578B2 (en) | Storage battery internal impedance measuring device and storage battery internal impedance measuring method | |
| JP2000338150A (en) | Watthour meter | |
| JPH0652277B2 (en) | Standard device with calculation function | |
| JPH01239473A (en) | Electronic type watthour meter | |
| JPS63238568A (en) | Creep preventing method for electronic watthour meter |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20031209 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20031222 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20080109 Year of fee payment: 4 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20090109 Year of fee payment: 5 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20090109 Year of fee payment: 5 |
|
| S533 | Written request for registration of change of name |
Free format text: JAPANESE INTERMEDIATE CODE: R313533 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20090109 Year of fee payment: 5 |
|
| R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20100109 Year of fee payment: 6 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20100109 Year of fee payment: 6 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110109 Year of fee payment: 7 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20120109 Year of fee payment: 8 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20120109 Year of fee payment: 8 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130109 Year of fee payment: 9 |
|
| LAPS | Cancellation because of no payment of annual fees |